Fabrication of Coral-like Pd based Porous MnO2 Nanosheet Arrays on Nickel Foam for Methanol Electrooxidation

Direct methanol fuel cells (DMFCs) have been seen as one of the desirable power sources, and the performance always depends on the ability of electrode materials to oxidize methanol. In this work, we report a novel electrode composed of coral-like Pd and porous MnO2 nanosheet arrays on nickel foam (Pd–MnO2/NF). MnO2 and Pd are successively electrodeposited on NF with different concentrations of PdCl2, which decides the shape of Pd and catalytic properties. Compared with Pd/NF, Pd–MnO2/NF exhibits excellent catalytic performance and good stability for methanol oxidation in alkaline solution. The mass activity of Pd–MnO2/NF with low Pd loading is 197.7 mA mg–1, which is 2.3-fold higher than that of Pd/NF. The improvement of performance mainly comes from MnO2, which supplies a number of oxygen atoms to reduce intermediates and enhance antipoisoning ability.